Concrete surfacing machine



Oct. 6, 1953 c F. YTTERBERG 2,654,298

CONCRETE SURFACING MACHINE Filed May 11, 1949 I 2 Sheets-Sheet l /i if! I .4 i;

a 5 4 .5? F o /7 ///v /7 fl if a 36 ATTORNEYS 2 Sheets-Sheet 2 Oct. 6, 1953 c F YTTERBERG I CONCRETE SURFACING MACHINE Filed May .m 1949 ATTORNE Y Patented Get. 6, 1953 CONCRETE SURFACIN G MACHINE Carl Frederick Ytterberg, Yonkers,

N. Y., assignor to Kalman Floor Company, Incorporated, New York, N. Y., a corporation of New York Application May 11, 1949, Serial No. 92,647

3 Claims.

1 Concrete surfacing machines of the power actuated type have been shown to be of substantial value when used to impart to the surfaces of freshly deposited concrete slabs the desired characteristics and such machines are being employed to an increasing extent. Numerous specific types have been proposed and certain of them placed in actual use, including machines of the rotary type comprising one or more work engaging members and an electric motor for moving the work engaging surfaces of such member or members about a vertical axis as the machine is advanced bodily.

The present invention relates to a concrete surfacing machine of the rotary type, more specifically to a rotary power driven machine. having a plurality of work engaging members in the nature of trowels, connected to a common frame, the assembly of frame and trowels being rotated about a vertical axis, when in use, by an electric motor of substantial size. Each of the trowels is connected to the common frame by means which has the capacity to absorb vibrations so that if, as preferred, the trowels are vibrated at high frequency, such vibrations are not communicated to the frame. It is thus possible to mount electric motors directly upon the frame and, in a preferred form of the invention hereinafter to be described in detail a number of motors are so supported, including a central motor of large size for effecting the rotation of the assembly about a vertical axis and several secondary motors, one adjacent each work engaging trowel. Each such secondary motor is connected by a belt or the like to an eccentric member rotatably mounted upon the adjacent work engaging trowel so that the trowel is mechanically vibrated whenever the motor is in operation.

The assembly described is largely of novel character, and likewise many of its details. The embodiment selected for disclosure by way of example is illustrated in the accompanying drawings, in which,

Figure 1 is a plan view of the apparatus;

Figure 2 is a side elevation;

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a section on line 4-4 of Figure 3;

Figure 5 is a section on line 5-5 of Figure 3;

Figure 6 is a section on line 6-6 of Figure 4; and

Figure 7 is a section on line 'l'! of Figure 3.

The motor frame is generally indicated at F and each trowel like work engaging member at T, the frame overlying all of the trowels and being provided with a. circular guard ring which prevents any member T from contacting a wall, post or other object when the machine is in use. Guard ring I0 is rigidly secured to the outer ends of tubular members II and the inner ends of these members are rigidly attached to the central disc [2 of the frame, as by welding. Members H are arranged in three groups of two each, the groups being equally spaced apart. angularly, and the two members of each group being preferably arranged in parallelism. Central disc I2 is provided with a hub l3 having an upwardly flaring socket or recess to receive the correspondingly tapered member [4, which is operatively connected, through gearing if desired, to the rotor of a motor the outer casing of which is indicated at M. The handle H is connected to the casing of motor M so that, when the apparatus is in use the motor casing will be positively held against rotation by the operator and the motor frame and trowel assembly caused to rotate about a vertical axis.

Each trowel T is disposed directly below a pair of the substantially parallel rod members II and is directly connected to each such member at two spaced points. The connecting devices are similar. Each includes means at its upper end for gripping or clamping one of the rod members H and means at its lower end for connecting that end to a bracket which is in turn rigidly secured to the trowel. One of these brackets may clearly be seen in Figure 5, being indicated at [6. It is disposed transversely of the trowel T upon which it is mounted and its ends are rigidly attached to the trowel by screw bolts [1. At its midpoint it is provided with a recess which receives a bearing I8 for rotatably supporting one end of the eccentric member l9 which extends lengthwise of the trowel, and intermediate this bearing receiving recess and its outer end has formed therein a cylindrical aperture 20 the axis of which is vertically disposed.

Within the aperture 20 is fitted a thin cylindrical sleeve 2|, the sleeve having a transverse flange 22 at its upper end and being secured in position in any suitable manner. A second sleeve 23 of much smaller diameter is disposed withinsleeve 2| and is coaxial with that sleeve. The space between the mutually facing surfaces of the two sleeves is occupied by a cushioning or vibration absorbing member 24, of rubber or other suitable resilient material, such member being annular in cross section and its inner and outer cylindrical surfaces being vulcanized to the surfaces of members 2| and 23 respectively. A vertical bolt 26 passes through sleeve 23, through aligned apertures in the rod member H directly above, and through apertures in the upper and lower rod clamping members 21 and 28, respectively. When the bolt is tightened the bracket l6 and rod II are firmly secured together but in such manner that any vibration of the associated trowel will not be communicated to the rod ll above but will the absorbed by the cushioning member 24. Four such securing means are associated with each trowel member and serve to attach that member at four spaced points to the two spaced rods H directly above.

Above each trowel T is a motor 30, such motor being connected to the associated eccentric 19 by means of a pulley 3i fixed on the end of the eccentric, a pulley 32 connected to the rotor of motor 30, through gearing if desired, and a connecting belt 33. Motor 30 is mounted upon a base 35 which is supported for rocking movement upon one of the rods H and adjustably supported upon the companion parallel rod. Thus base 35 is mounted for rocking movement upon the left hand rod (Figure and an adjusting screw 36 passing through a threaded aperture in a boss 31 at the other end of the motor base has its lower end at all times in engagement with the right hand rod H shown in Figure 5. By rotating the screw 36 the motor base may be tilted and the motor bodily adjusted toward or away from the trowel T below. The tension in each belt 33 may be thus adjusted as desired. The mains for supplying the motors with electric current are not shown and any convenient wiring system may be utilized. Preferably current. will be transmitted to the motors on the rotating frame through brushes such as it and H, mounted on ,thedisc 12, which brushes are in constant contact with rings 42 and B3, respectivcly, secured to the underside of an insulating plate 45 attached to the stationary motor casing. A protective casing 46. encloses these parts. The rings 42 are connected to a stationary source of electric current by wires which may conveniently pass alongthe handle H to its upper end, and thence to that source, as is customary in power operated surfacing machines of this class. The brushes 40 and 4!, which are urged upwardly into contact with rings 43 and 42, respectively, by springs such as the helical springs illustrated, of .course rotate with the frame upon which motors 30 are mounted and each brush will be connected to each of the motors by a suitably arranged. and supported wire, in the manner thought most convenient.

It will be appreciated that, for certain of the elements disclosed others may be substituted without sacrifice of function or result and that there may be some rearrangement without departure from the invention. In every instance, however, the eccentric means for effecting vibration of a trowel member will be rigidly secured to that member, the eccentric driving-motor will be on the motor frame, and the connecting devices will include vibration absorbing parts.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a concrete surfacing machine, in combination, a plurality of work engaging trowels, a motor frame above the trowels, spaced brackets mounted upon and extending transversely of each such trowel, an eccentric rotatably supported in said spaced brackets, a driving motor centrally mounted on the motor frame, a plurality of secondary motors mounted on said motorx frame, one adjacent each trowel, a vibration absorbing driving connection between each bracket and the motor frame, and a driving connection between each eccentric and the secondary motor associated therewith.

2. The combination set forth in claim 11 in which the motor frame comprises a central mem her and a plurality of arms extending outwardly therefrom, said arms being arranged, in pairs; one of the secondary motors bridging and bein supported by the arms of each pair. w

3. The combination set forth in claim 1 in which the motor frame comprises a, central'r'nemher and a plurality of arms mounted rig-idly thereon and extending outwardly therefrom, said arms being disposed in pairs, one of said second ary motors being rockably mounted on one arm of each pair of arms and being adjustably sup ported on the other arm.

CARL FREDERICK YITERBERG.

References Cited in the file of this patent UNITED STATES PATENTS 

